by Dave Berg , USA TODAY

by Dave Berg , USA TODAY

After months of speculation, the end of Jay Leno's reign as host of NBC's Tonight Show is now certain. The ever affable Jimmy Fallon takes over television's longest-running entertainment program sometime in 2014 when Leno's contract runs out.

Television critics and media observers have resented Leno since 1992 when he got the gig instead of David Letterman. They have never shown him the respect he deserves. In the parallel universe they've created, David Letterman was the rightful heir to Johnny Carson's throne, and is, therefore, the king of late night.

Letterman himself recently acknowledged Jay's comedic prowess, telling Oprah he thinks Leno is "the funniest guy I've ever known." But not the critics. You would think from what they write, Leno has been a mere interloper, a bit player in late night.

In fact, he continues tobe No. 1 in the ratings,even in the coveted 18-49 demographic, despite NBC's dismal decade-long primetime schedule, which recently dropped into fifth, well behind the Spanish-language network Univision.

What critics don't understand is how the business works, so let's set the record straight. NBC chose Leno to replace Johnny Carson because the network believed he would do a better job than Letterman, not because Leno somehow manipulated the selection process, as Leno's detractors suggest.

Then GE Chairman Jack Welch was the one who hired Leno. Welch later told me he had a gut feeling Leno was the better man, and that Letterman seemed "uncomfortable in his own skin." Welch was a bottom-line guy, and by those standards he was right. Letterman's supporters, like Los Angeles Times critic Robert Lloyd see their guy as an artist: "There is no desperation in his presentation; he does not need to impress you, or the celebrities who sit next to him."

Leno, on the other hand, believes he does need to impress you. To him, show business is as much about the business as the show, and his primary job is to deliver the most demographically-correct viewers. Art has nothing to do with it.

Leno has always reached out to his entire audience, including people in the red, flyover states. But critics dismiss those Leno stalwarts as unworthy viewers because they aren't capable of understanding the sophisticated humor of Letterman and John Stewart. I happen to think those guys are funny, but shouldn't Leno get a little credit? Except for a seven-month stretch in 2009-2010 when Conan O'Brien hosted the show, Leno has had the most viewers in late night for 18 straight years,

Leno, an admitted social liberal/fiscal conservative, advises guests on his show not to cut off 50% of their potential audience by doing only left-leaning jokes. In the great tradition of Johnny Carson, he has consistently delivered the most political, yet even-handed monologue in the business.

It's no secret Hollywood favored Barack Obama in the recent presidential election, and Leno's competitors almost never did jokes about Obama, while doubling down on Mitt Romney zingers. Leno's monologue spared none of the candidates -- including Obama -- throughout the election cycle. My favorite was a one-liner about ObamaCare: "You think health care is expensive now. Wait 'til it's free." Yet, Leno is criticized for doing "safe jokes."

Leno also pioneered the idea of interviewing presidential candidates during primary and presidential elections. His biggest achievement: booking Obama on March 19, 2009 -- his 59th day in office -- the first late-night appearance by a sitting president.

Last year Leno's political bookings were way out in front of his competitors. His "gets" included an exclusive late-night interview with Mitt Romney, almost all of the other GOP presidential hopefuls and President Obama, as well as Michelle Obama and Ann Romney.

NBC has a right to replace Leno with Jimmy Fallon, a genuinely funny guy, even though I think it's short-sighted. But the execs, like the critics, have never acknowledged Leno's impressive late-night legacy. He has propped up their sorry network for years, despite their best efforts to run its primetime schedule into the ground with such recent ratings downers as Smash and Do No Harm.

In January, NBC Entertainment Chairman Bob Greenblatt denied there were any talks with Fallon to replace Leno, then got upset when Leno did jokes about the network's poor ratings. Leno shot back by calling NBC executives "snakes." But I don't agree. Snakes aren't that bad.

Dave Berg worked 18 years as a co-producer for The Tonight Show with Jay Leno. He's now writing a book about it.

In addition to its own editorials, USA TODAY publishes diverse opinions from outside writers, including our Board of Contributors.